Portable power supply



FIG. 1 is a front view of a portable power supply showing the new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a left view thereof;

FIG. 4 is a right view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom side view thereof;

FIG. 7 is a perspective view thereof.

FIG. 8 is another perspective view thereof;

FIG. 9 is an enlarged detail view of the area indicated in the FIG. 1; and,

FIG. 10 is an enlarged detail view of the area indicated in the FIG. 5.

The broken lines in the figures depict portions of the article which form no part of the claimed design.

The dot-dash broken lines indicate areas of enlarged detail view and form no part of the claimed design. 

CLAIM The ornamental design for a portable power supply, as shown and described. 